Differential neural structures, intrinsic functional connectivity, and episodic memory in subjective cognitive decline and healthy controls

N. Nellessen, O.A. Onur*, N. Richter, H.I.L. Jacobs, K.N.H. Dillen, B. von Reutern, K.J. Langen, G.R. Fink, J. Kukolja

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

The neural correlates of subjective cognitive decline (SCD; i.e., without objectifiable deficit) remain to be elucidated. Possible causes of SCD include early neurodegeneration related to Alzheimer's disease or functional and structural changes related to sub-clinical depression. We investigated the relationship between episodic memory performance or memory complaints and structural or functional magnetic resonance imaging (MRI) measures in participants with SCD ( n = 18) but without psychiatric disorders and healthy controls ( n = 31). In SCD, memory complaints were not associated with memory performance but with sub-clinical depression and executive functions. SCD-associated memory complaints correlated with higher amygdala and parahippocampal gyrus (specifically subiculum) gray matter density. In controls, but not in SCD, mesiotemporal gray matter density and superior frontal gyrus functional connectivity predicted memory performance. In contrast, in SCD, only a trend toward a correlation between memory performance and gray matter density in the parietooccipital lobes was observed. In our memory-clinic sample of SCD, we did not observe incipient neurodegeneration (limited to structural and functional MRI) but rather sub-clinical depression underlying subjective cognitive complaints. (c) 2021 Elsevier Inc. All rights reserved.
Original languageEnglish
Pages (from-to)159-173
Number of pages15
JournalNeurobiology of Aging
Volume105
DOIs
Publication statusPublished - 1 Sep 2021

Keywords

  • MRI
  • Medial temporal lobe
  • Hippocampus
  • Voxel-based morphometry
  • Default-mode network
  • Frontoparietal control network
  • INDEPENDENT COMPONENT ANALYSIS
  • DEFAULT-MODE NETWORK
  • HUMAN CEREBRAL-CORTEX
  • RESTING-STATE FMRI
  • EVENT-RELATED FMRI
  • ALZHEIMERS-DISEASE
  • OLDER-ADULTS
  • INCREASED AMYGDALA
  • ENTORHINAL CORTEX
  • PROCESSING SPEED

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